Northwestern University biologist Jonathan Tilly is certain
he’s found egg-making stem cells in adult mice. If he’s right, it would refute
decades-old work that showed female mammals finish making all their eggs before
or shortly after birth. This might make it possible to grow new eggs inside the
ovaries of older women.
In a feature for Science last week, Jennifer Couzin-Frankel
wrote about the ongoing scepticism many reproductive biologists have towards
both Tilly’s work and OvaScience, the fertility-treatment company he helped
found.
Tilly says he’s proven the existence of these stem cells by
every method imaginable. But sceptics, and there are many, argue that he has
relied chiefly on appearance and genetic markers to identify them. Most
reproductive biologists insist that the cells be caught in the act of
undergoing meiosis, the cell division unique to sperm and eggs in which bits of
DNA are swapped between chromosomes. They also want to see that the resulting
eggs can be fertilised and create offspring.
In short, before reproductive biologists are willing to
agree that Tilly has found precursors of eggs, they want to see evidence that
these cells actually turn into eggs.
Nevertheless, OvaScience has pressed on: it now offers their
first modification of standard IVF based on the disputed research in Canada,
Panama, Spain, Turkey, and Dubai. In the AUGMENT treatment, mitochondria are
isolated from the putative immature egg cells and injected into a patient’s egg
along with a sperm cell.
AUGMENT costs $US25,000 on top of the astronomical costs of
a ‘normal’ round of IVF, and although the company claims the technique can give
older eggs additional energy for early development, so far all of its successes
have been in younger women. Some critics say AUGMENT’s chances of success are
no different than normal IVF: if true, women using it could be doubling the
price of their treatment for no good reason.
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